Low-Vt small-offset gated preamplifier for sub-1V gigabit DRAM arrays

A sensing scheme with temporary activation of a low-V, gated preamplifier (LGA) achieves fast sensing, fast local I/O driving and low-leakage operation simultaneously even for low-voltage mid-point sensing. The features are verified with a 70 nm 128 Mb DRAM core that demonstrates 16.4 ns row access (tRCD) and 14.3 ns read access (tM) at an array voltage of 0.9 V. The LGA is promising for future sub-1 V gigabit DRAMs because it reduces variation in threshold voltage (Vt) of MOSFETs and in the offset voltage of sense amplifiers.